Factors associated with dose reduction of pirfenidone in patients with idiopathic pulmonary fibrosis: A study based on real-world clinical data

PLoS One. 2023 Feb 3;18(2):e0281295. doi: 10.1371/journal.pone.0281295. eCollection 2023.


Introduction: Although pirfenidone slows disease progression in patients with idiopathic pulmonary fibrosis (IPF), in clinical practice, patients often cannot tolerate the recommended dose because of several adverse events. This study aimed to investigate adverse events associated with pirfenidone and factors associated with dose reduction.

Methods: This single-center retrospective cohort study included 156 consecutive patients with IPF who received pirfenidone. Demographic characteristics, pulmonary function, and pirfenidone-related adverse events were investigated. We compared patients who received standard and reduced doses of pirfenidone.

Results: The mean patient age was 69.7 years. The median follow-up duration was 243 days. The low-dose group (n = 73) included older patients (71.0 years vs. 67.4 years, p = 0.016), fewer smokers (80.8% vs. 96.4%, p = 0.008), and patients with a lower body mass index (BMI; 24.1 kg/m2 vs. 25.7 kg/m2, p = 0.027) than the standard dose group (n = 57). Multivariate logistic regression analysis revealed that older age (odds ratio = 1.066, p = 0.016) was significantly associated with dose reduction of pirfenidone after adjusting for sex, smoking history, emphysema, and BMI. No significant difference was found in the rates of a reduced forced vital capacity and diffusing capacity for carbon monoxide between the two groups.

Conclusions: Although older patients are more likely to undergo dose reduction of pirfenidone, low-dose pirfenidone might be effective for treating patients with IPF. Low-dose pirfenidone could be considered an effective treatment option for older patients with IPF.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aged
  • Anti-Inflammatory Agents, Non-Steroidal / adverse effects
  • Drug Tapering*
  • Humans
  • Idiopathic Pulmonary Fibrosis*
  • Pyridones / adverse effects
  • Retrospective Studies
  • Treatment Outcome
  • Vital Capacity


  • pirfenidone
  • Anti-Inflammatory Agents, Non-Steroidal
  • Pyridones

Grants and funding

This study was supported by a grant (grant number: 2022IL0021) from the Asan Institute for Life Sciences, Asan Medical Center, Seoul, Korea and Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Education (2022R1C1C1005736). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.